4 Photocatalytic Oxidative C–C Bond Formation

Abstract This chapter summarizes some important examples of carbon–carbon bond-forming reactions at the α-position of tertiary amines using photoredox catalysis. The photocatalytic single-electron oxidation of tertiary amines leads to the generation of an amine radical cation, from which two highly reactive and synthetically useful intermediates, iminium ions and α-aminoalkyl radicals, can be produced. Iminium ion intermediates, being electrophilic in nature, react with a range of carbon nucleophiles forming new carbon–carbon bonds. On the other hand, the α-aminoalkyl radical, an electron-rich radical, adds efficiently to electron-deficient unsaturated systems resulting in carbon–carbon bond-forming reactions. This chapter also highlights some examples of carbon–carbon bond-forming reaction by nucleophilic/radical addition to photocatalytically generated arene radical cations.